Cart
|
[XSL-LIST Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: XSLT 4 xsl:with
 A contrived example follows. Consider this variable: <xsl:variable name="baz" as="element(baz)">
<baz>
<bar>
<foo n="1"/>
<foo n="2"/>
</bar>
</baz>
</xsl:variable>Then a template might create this output tree: <xsl:for-each select="$baz/bar">
<td>
Count of foo elements in {path()}:
<xsl:value-of select="count(foo)"/>
</td>
</xsl:for-each>(The stylesheet author preferred to switch context to $baz/bar in order to "simplify" expressions.) With @xsl:context-item, this can be written as: <td xsl:context-item="$baz/bar">
Count of foo elements in {path()}:
<xsl:value-of select="count(foo)"/>
</td>or in an xsl:message: <xsl:message context-item="$baz/bar">
Count of foo elements in {path()}:
<xsl:value-of select="count(foo)"/>
</xsl:message>On elements such as xsl:for-each and xsl:copy, @context-item will have the same semantics as the existing @select attribute. Therefore it need not be allowed on these elements. (Maybe xsl:copy/@select would have better been named @context-item in the first place.) Another example with xsl:choose: <xsl:choose context-item="$baz/bar"> <xsl:when test="count(foo) = 2">...</xsl:when> <xsl:otherwise>...</xsl:otherwise> </xsl:choose> This one combines @context-item with the @select attribute on xsl:when, as proposed by Michael Kay at this year's XML Prague: <xsl:choose>
<xsl:when context-item="$baz/bar"
test="count(foo) = 2" select="'two'"/>
<xsl:when test="count($baz/bar/foo) = 1">
<xsl:sequence select="'one'"/>
</xsl:when>
<xsl:otherwise>...</xsl:otherwise>
</xsl:choose>I'm not sure though whether all occasions on which people use xsl:for-each merely to switch context can be substituted with this context-item attribute. Sometimes the xsl:for-each instruction will comprise many result tree elements or XSLT instructions. Then there is no single element to stick the @context-item attribute onto. The common case of one or more xsl:variable declarations in the new context can be replaced by not switching context, but instead by declaring the variables or the first variable with a @context-item: <xsl:variable name="count" as="xs:integer" select="count(foo)" context-item="$baz/bar"/> <xsl:variable name="is-positive" as="xs:boolean" select="$count gt 0"/> (Don't tell me that I don't need all these variables; this is a contrived example.) -- Gerrit On 19.05.2020 14:00, Graydon graydon@xxxxxxxxx wrote: On Tue, May 19, 2020 at 08:53:54AM -0000, Pieter Masereeuw pieter@xxxxxxxxxxxx scripsit:I would be very happy if I could make my intentions clearer by using a real XSLT construct in this situation, such as *<xsl:with select="...">*. The semantics could also help as an assertion that, indeed, the selection has exactly length 1. 
|
PURCHASE STYLUS STUDIO ONLINE TODAY!Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced! 
Download The World's Best XML IDE!Accelerate XML development with our award-winning XML IDE - Download a free trial today! Subscribe in XML format
|
